MedStar (formerly Medlantic) Research Institute proposes to continue its participation in the Strong Heart Study to manage the Arizona field center and the core laboratory. For the field center, this proposal describes methodology for 1) morbidity and mortality surveillance of the original Strong Heart Study cohort (1099 surviving out of 1500 original men and women ages 45-74 years in Phase I); 2) recruitment and examination of 30 families of at least 30 members, each 15 years and older; and 3) re- examination of the 900 family members from the Phase Ill pilot study. The Arizona field center comprises three American Indian communities: Gila River, Salt River, and Ak Chin. The Arizona center had a 71% recruitment rate in Phase I and 90%+ completion rates in Phases II and III. Morbidity and mortality surveillance obtained data on 99% of the participants. The core laboratory will provide accurate, reliable, stable, and comparable phenotypic measures of coronary heart disease risk factors in blood and urine samples. Measurements to be made for the family cohort include lipoprotein profile, glucose, HbA1c, insulin, LDL size, fibrinogen, PAI-1, apoE phenotype, apoB, apoA1, chemistry profile, and urinary albumin and creatinine. In addition, some exciting new markers of evolving importance in the etiology of atherosclerosis will be evaluated on stored baseline samples using a case-cohort design. sVCAM and endothelin-1 will be measured in approximately 400 definite cardiovascular disease cases and suitable controls. TSH also will be measured in these samples to allow evaluation of its role in cardiovascular disease in American Indians. The core laboratory will store blood, urine, and DNA in a safe and organized manner for effective inventory so that the resources will be retrievable for other scientists and the American Indian communities. Laboratory performance during the previous exams has been excellent, with high completion rates and precision and accuracy exceeding those of most core laboratories.